Lentman Lake Dam Reservoir Report

Last Updated: December 26, 2025

Lentman Lake Dam, also known as The Reservoir, is a privately owned structure located in Livingston County, Illinois.


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Summary

Completed in 1965, this earth-type dam stands at a height of 12 feet and spans a length of 310 feet. It serves primarily for recreational purposes, offering a storage capacity of 198 acre-feet and a normal storage level of 74 acre-feet. The dam overlooks the Vermilion River-offstream and is regulated by the Illinois Department of Natural Resources.

Despite its low hazard potential, Lentman Lake Dam poses a high risk due to unspecified factors. The dam has not been assessed for its condition, and information about emergency action plans and risk management measures is currently unavailable. The last inspection conducted in June 2016 revealed no major concerns, with an inspection frequency of every 5 years. It is important for stakeholders and authorities to prioritize the safety and maintenance of Lentman Lake Dam to ensure its continued functionality and mitigate potential risks.

Located in the city of Streator, Lentman Lake Dam offers a picturesque setting for water resource and climate enthusiasts to explore. With its serene surroundings and recreational opportunities, the dam serves as a valuable asset to the community. As efforts are made to enhance its safety and resilience, Lentman Lake Dam remains a focal point for outdoor activities and environmental appreciation in Livingston County, Illinois.

Year Completed

1965

Dam Length

310

Dam Height

12

River Or Stream

VERMILION RIVER-OFFSTREAM

Primary Dam Type

Earth

Nid Storage

198

Outlet Gates

None

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

12
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.